Bone cells derived from a variety of animal species including human, bovine, ovine and rodent, and of varying developmental ages, have been utilized to: 1) study the biosynthesis and deposition of extracellular matrix proteins such as collagen, osteonectin, bone proteoglycan and other bone proteins, and alterations of matrix production in the disease Osteogenesis Imperfecta; 2) study the responsiveness of the cells to a variety of hormonal and pharacoloical factors (such as 1,25-dihydroxy vitamin D3 and fluoride); 3) elucidate the production and interaction of growth factors (such as TGF-beta, insulin-like growth factors and platelet-derived growth factors); 4) study the potential function of bone matrix proteins through the use of functional assays and the use of anti-sense DNA to inhibit specific protein synthesis; 5) serve as a source of mRNA and DNA for studies of the proteins at the genomic level.